Aeroplane control



July 28, 1931. c. M'OCAR OLL 1,816,688

AEROPLANE CONTROL Filed Aug. 22. 1929 5 Sheets-Sheet 1 g ga I BY 1 i ATTORNEY INVENTOR y- 8 3 8 c. mc RRqLL 1,818,888

AEROPLANE CONTROL. v

Filed Aug. 22,1929 8 3 Sheets-Sheet 2 WITNESS d 67 INV.ENTOR 40 1161. fil "Carri? ATTORNEY July 28,1931. c. McCARROLL ,6

AEROPLANE CONTROL Filed Aug. 22. 1929 3 Sheets-Sfieet s INVENTOR 19 E35 Chou n ar/flu Qcssawm w BY 1w K 0 ATTORNEY Patented July 28, 1931 UNITED STATES A CHARLES MCCARROLL, OF KINGSPOB'I, TENNESSEE AEROPLAN E CONTROL Application filed August 22, 1929. Serial No. 887,715.

This invention relates to an automatic control apparatus for aeroplanes. I

As is well known, an aeroplane operates at its greatest efficiency and safety when its longitudinal axis is maintained parallel to the approaching sweep of air. This is the efficient and safe flying condition of a plane;

, but due to the slowness of manually actuatedoperation of the rudder and elevating planes of an aeroplane this position is not accurately maintained at all times, with the result that unsafe and inefficient flying conditions are brought about. As for example, an aeroplane when easing velocity to a degree insufficient to support its weight brings about a condition known as stalling. Under this condition I the air instead of approaching straight toward the aeroplane, is approaching at an upward angle, and not parallel with a center line through the body of the aeroplane or longi tudinal axis thereof. Again, if the aeroplane is flying at an excessive speed'the approaching sweep of air is at a downward angle. This last condition effects the efficiency of operation of the aeroplane while the stalling con dition efl'e'cts the safety thereof.

Still another condition effecting safety and efliciency is that known as side slipping. which is primarily due to improper correlation between the manipulations of the aeroplane controls, namely the rudder and elevating planes. When a side-slip takes place the approaching'sweep of air is at a lateral angle to the longitudinal axis of the aeroplane body instead of parallel thereto as is necessary for safe and eflicient operatio;.-

With that heretofore set forth in view, it

is an objectof this invention to provide a control apparatus capable of operating the rudder and elevating planes foraccurately maintaining the longitudinal axis of an aeroplane, while in flight, parallel to the approaching sweep of air at. all times and under various operating conditions. a

It is also an object of the invention that the control apparatus be entirely automatic in operation.

A further object of the invention is to provide instrumental means operable in conjunction with the control apparatus for in- 5 .dicating at all times the parallel position of the longitudinal axis of the aeroplane with respect to the approaching sweep of air. 7

. It is also within the scope of the objects j of the invention that the control apparatus and indicating means, operating in conjunction therewith, be positive and certain in operation. a The invention is illustrated by waypf example in the accompanying drawmgs, in (so which Figure 1 is a topplane view of an aeroplane with my invention applied,

Figure 2 is a side elevation of the same, Figure 3 is a perspective view of the lever control mechanism of this invention located in the cock-pit of an aeroplane and also showing in elevation the instrument board for the indicating instruments that may be utilized,

Figure 4 is a diagram illustrating the automatic operating means for the elevator planes, Figure 5 is a schematic view showin the operating means for both the rudder an elevating planes, and the indicating devices used in conjunction therewith, and

In carrying out my'invention I provide what I term a control or tangency vane generall designated by reference numeral 16. It Wlll be observed that the control vane is positioned inundisturbed air. The control vane, as shown to advantage in Figures 1 and l0 2, is located in front of the main planes and outside of the propeller slip stream or wash. This position renders the control vane sensi tive to the direction of the approaching and passing sweep of air. The control vane is mounted to permit self-adjustment for parallelism with the passing sweep of air; and by the provision of circuits and mechanism operating in conjunction with the control vane hereinafter to be described. I am able to operate the rudder and elevator planes to maintain the longitudinal axis of the aeroplane parallel with the approaching and passing sweep of air in a highly accurate manner. 4

Referring to Figures 4, 5 and 6, the control vane comprises a shaft 17 one end of which is journaled within the forward part of the aeroplane body by bearings 18, Figure 5. The shaft extends laterally from the aeroplane and its outer end terminates in a U- shaped member 19 which has journaled between the leg portions a stub-shaft 20. The stub-shaft 20 rigidly supports a rod 21 preferably as shown in Figure 4. The forward end of rod 21 carries a weight 22 and its rear end carries a pair of fins 23 and 24. These fins are preferably'of the shape shown, the fin 24. being disposed in a horizontal plane while the fin 23 is disposed at right angles to fin 24.

A rod 25 is arranged parallel with shaft- 17 and its outer end pivoted as at 26 to the forward end of the rod 21. Rod 25.,is supported for longitudinal movement by a suitable guide bracket as at 27. The inner end of rod 25 carries a contact 28 adapted for engaging contact 29 or contact 30.

Now referring to Figure 3, 31 indicates a pilot seat, and .32 an instrument board. At 33 is shown a hand leven, which is connected through gables 34 in the conventional manner with ailerons 15 ;at 35 is shown a second hand lever'whichis connected through cables 36 for operating the rudder 14; and at 37 is shown a third hand lever connected through cables 38 for operating the elevators The lever 37 carries an eleetromagnet 39 which has projecting therefrom an elongated arcuate armature-rod 40. The rod 40 is freely movable through an electromagnet 41 which is carried by a suitable bracket 42. Likewise, lever 35 carries an electromagnet 43 provided with an elongated arcuate armature-rod 44 freely movable through an electromagnet 45 supported by bracket 46 Now referring to Figure 5 it will be seen that the contacts 29 and 30are connected to opposite sides of a battery 47 through theleads 48 and 49 respectively. The electromagnet 43 is connected across the leads 48 and 49 by leads 50 and 51, while the electromagnet 45 is connected in series with the cone 39 isv connected. across these leads through leads 61 and 62. Electro-magnet 41 is connected in series with the mid-point 52 of battery 47 and contact finger 56 through leads 63 and 64. It should be noted that the shaft 17 is forward to the instrument board 32.

The shaft 17 is provided with a weighted arm 66 the purpose of which will later appear. The arm carries on its free end a graduated scale 67 which registers with a Window 68 in the instrument board. The arm 55 also carries a T-shaped member 69 adapted to serve as a sighting device. The horizontal portion 70 may be observed through a suitable slot 71. Shaft 17 has an arm 72 carrying at its free end a level 73 that may be observed through a window 74 in the instrument board A rod 75 has its one end pivoted as at 76 to red 27 and its other end supporting an arcuate shaped scale 7 6 which registers with a window 77 in the instrument board 32. The rod 75 is further supported as at 76 by shaft 17 to permit lateral swinging movement of the rod as indicated by the line 77.

' In the use of the apparatus heretofore described,-during flight of an aeroplane the control vane is at all times maintained parallel to the approaching sweep of airby' the fins 23 and 24. The weights 22 and 66 assist the vane 15 in maintaining this position. Should the aeroplane be operated at excessive speed, and the approaching sweep of air be at a downward angle to the main planes, the fin 24 will shift to a position parallel with the approaching sweep of air. This will swing rod 21 downward in the direction of the arrow d in Figure 4 and rotate the shaft 17 to bring contact finger 56 in engagement with contact 57 and thereby establish circuits for energizing the electromagnets 39 and 41 for shifting lever 37 to operate the elevator planes 13 for adjusting the position of the aeroplane so that its longitudinal axis is parallel to the approaching sweep of air. Should the speed of the aeroplane decrease to such' an extent that it would not sustain its weight and the approaching sweep of air be at an upward angle to the main planes 11, the fins 24 would swing the-rod 21 upward and cause the contaet finger 56 to engage contact 58 and thereby'establish circuits for energizing the electro-mag'nets to operate the lever 37 and elevator planes 13 to bring the longitudinal axis parallel 'th the approaching sweep of air.

It should here be noted that the downward and upward swinging movements of arm 55 can be obs'erved through window 68. If the scale 67 is equally divided as shown the arrow 80 would indicate the position the midpoint of the scale should register for indicating that the plane is accurately proceeding with relation to the approaching sweep of air.'- The sighting device 69 also will move upward and downward with arm 55. However, if the aeroplane is proceeding properly, the pilot can in an obvious manner use the top portion 70 of the device 69 for ascertaining where the aeroplane will land, or its path of travel.

Referring to the spirit level 7 3 carried by the arm 72, it will be assumed the level is so disposed that, when the aeroplane is flying properly, .Viz., with its longitudinal axis parallel to the approaching sweep of air, the level will thus show proper travel gradient at all times of the aeroplane.

Should the aeroplane be flying in a manner to bring about side slipping the control vane 16, rod 25, associated circuits of contacts 28, 29 and 30, and electro-magnets 43 and 45 would operate to correct such side slip through rudder 14 and bring the aeroplane to such a position that its longitudinal axis would be parallel tothe approaching sweep of air. If the approaching sweep of air was in such a direction as to cause the vane 23 to swing the rod 21 in the direction of arrow a then the contact 28 would engage contact 29 and establish-circuits for energizing the electro-magnets 43 and 45 to operate rudder 14 to correct the flying position of the aeroplane, viz., bringing the aeroplane to such a position that its longitudinal axis is parallel to the-approaching sweep of air. In case the approaching sweep of air issuch that the rod 21 is swung in the direction of arrow 6 then the contact will engage contact 30 and establish circuits through electro-magnets 43 and 45 to operate the rudder 14 to bring the aeroplane to its proper position.

It should be noted that with the lateralswinging movements of the rod 21 heretofore described, the rod will be correspondingly actuated to swing upon its pivot 76. This movement of the arm 7 5, will be indicated by scale 76; as shown in Figure 3 the scale 7 6 may be divided and thus enable the pilot to ascertain. if any side slipping of h1s aeroplane is taking place.

While I have shown and described certain preferred means whereby my invention may be practiced, I wish it to be understood that I am aware of the fact that the general arrangement and combination of parts might be changed by those skilled in the art without departing from the spirit of my invention as indicated by the appended claims.

-1. In combination with an aeroplane, a

rotatable shaft extending laterally therefrom, a rod supported by said shaft, fins carried by the rod adapted to cause rotation of the shaft in maintaining the rod in parallel to the approaching sweep of the air, an arm extending from the shaft, and a sighting member carried by said arm whereby the path of travel of the aeroplane may be determined.

2. In combination with an aeroplane, a 1'0- tatable shaft extendinglaterally therefrom, a rod supported at the end of the shaft for both lateral and vertical swinging movement, fins carried by the rod adapted for swinging the rod both laterally and vertically for maintaining the same parallel. to the ap proaching sweep of air, and means whereby the lateral and vertical swinging movements of the rod are utilized for maintaining the longitudinal axis of the aeroplane parallel to the rod.

3. In combination with an aeroplane, a ro- 'tatable shaft extending laterally therefrom,

a rod supported at the end of the shaft for both lateral and vertical swinging move ment, fins carried by the rod adapted for swinging the rod both laterally and vertical- 1y for maintaining the same parallel to the approaching sweep of air and means whereby the degree of lateral swinging movement of the rod may be indicated to the operator of the aeroplane.

4. In a control device for aeroplanes or the like, a rotatable shaft extending laterally therefrom, a rod pivotally mounted upon the end of the shaft for both lateral and vertical swinging movements, fins carried by one end of the rod adapted for swinging the rod both laterally and vertically, a reciprocating rod connected to the other end of said first named rod, control levers, electrical circuits associated therewith having a plurality of contacts in the path of said shaft and reciprocating rod whereby upon rotation of said, shaft or reciprocation of said rod the electrical circuit will be completed for effecting control whereby rotation of said shaft or reciprocation of said rod theelectrical circuits will be completed for effecting movement of said control levers, and separate indicator means associated with said shaft and said rod for indicating to an operator the degree of movement of said shaft or rod.

6. In a control device for aeroplanes or the like, a rotatable shaft, a reciprocating rod, a single means having lateral and vertical swinging movements for independentl rotating said shaft and reciprocating sai rod, electrical circuits associated with said shaft and rod, a pair of control levers, electro-magnets for each of said levers connected in said electrical circuits, and contact-means carried by said shaft and said reciprocating rod for independently energizing respective electromagnets forvcontrol of said aeroplane.

I CHARLES MCCARROLL. 

